Handle unquoted pipes. (unioslo#180)

- Prevents the CLI from dying when confronted with commands like `permission network_add 123.123.123.0/27 some-group-name ^[a-z0-9\-]+(\.(aa|bbb|ccc|sikkerhet?\.uio\.no$`
  - To allow for reuse of exception formatting, moves the formatting to the exceptions themselves rather than leaving the issue for the user.

mreg_cli/cli.py

@@ -139,11 +139,8 @@ def parse(self, command: str) -> None:
             # after it prints a help msg.
             self.last_errno = e.code
 
-        except CliWarning as e:
-            print_formatted_text(HTML(f"<i>{e}</i>"))
-
-        except CliError as e:
-            print_formatted_text(HTML(f"<ansired>{e}</ansired>"))
+        except (CliWarning, CliError) as exc:
+            exc.print_self()
 
         except CliExit:
             from sys import exit

mreg_cli/exceptions.py

@@ -1,13 +1,46 @@
+"""This module contains custom exceptions for the CLI."""
+
+import sys
+
+from prompt_toolkit import print_formatted_text
+from prompt_toolkit.formatted_text import HTML
+
+
 class CliException(Exception):
-    pass
+    """Base exception class for the CLI."""
+
+    def formatted_exception(self) -> str:
+        """Returns a formatted string representation of the exception.
+
+        :returns: Formatted string for the exception message.
+        """
+        raise NotImplementedError("This method should be implemented by subclasses")
+
+    def print_self(self):
+        """Prints the exception with appropriate formatting."""
+        print_formatted_text(HTML(self.formatted_exception()), file=sys.stdout)
 
 
 class CliError(CliException):
-    pass
+    """Exception class for CLI errors."""
+
+    def formatted_exception(self) -> str:
+        """Formatted string with ANSI red color for the error message.
+
+        :returns: Formatted error message.
+        """
+        return f"<ansired>{super().__str__()}</ansired>"
 
 
 class CliWarning(CliException):
-    pass
+    """Exception class for CLI warnings."""
+
+    def formatted_exception(self) -> str:
+        """Formatted string with HTML italic tag for the warning message.
+
+        :returns: Formatted warning message.
+        """
+        return f"<i>{super().__str__()}</i>"
 
 
 class HostNotFoundWarning(CliWarning):

mreg_cli/main.py

@@ -8,6 +8,7 @@
 
 from . import config, log, recorder, util
 from .cli import cli, source
+from .exceptions import CliError, CliWarning
 from .outputmanager import OutputManager
 
 logger = logging.getLogger(__name__)
@@ -187,8 +188,10 @@ def main():
                 cli.parse(cmd)
                 # Render the output
                 output.render()
-        except ValueError as e:
-            print(e)
+        except (CliWarning, CliError) as exc:
+            exc.print_self()
+        except ValueError as exc:
+            print(exc)
 
 
 if __name__ == "__main__":

mreg_cli/outputmanager.py

@@ -8,6 +8,8 @@
 import re
 from typing import Any, List, Tuple
 
+from mreg_cli.exceptions import CliError
+
 
 class OutputManager:
     """Manages and formats output for display.
@@ -42,7 +44,7 @@ def from_command(self, command: str) -> str:
         """Adds the command that generated the output.
 
         :param command: The command to add.
-
+        :raises CliError: If the command is invalid.
         :return: The cleaned command, devoid of filters and other noise.
         """
         self._command, self._filter_re, self._negate = self.get_filter(command)
@@ -113,6 +115,7 @@ def get_filter(self, command: str) -> Tuple[str, Any, bool]:
         splitting.
 
         :param command: The command to parse for the filter.
+        :raises CliError: If the filter is invalid.
         :return: The command, the filter, and whether it is a negated filter.
         """
         negate = False
@@ -129,7 +132,17 @@ def get_filter(self, command: str) -> Tuple[str, Any, bool]:
                     negate = True
                     filter_str = filter_str[1:].strip()
 
-                filter_re = re.compile(filter_str)
+                try:
+                    filter_re = re.compile(filter_str)
+                except re.error as exc:
+                    if "|" in filter_str:
+                        raise CliError(
+                            "ERROR: Command parts that contain a pipe ('|') must be quoted.",
+                        ) from exc
+                    else:
+                        raise CliError(
+                            "ERROR: Unable to compile regex '{}': {}", filter_str, exc
+                        ) from exc
 
         return (command, filter_re, negate)